Unknown Nest thermostat passcode from previous owners

[cath1]

Previous owners installed a Nest thermostat.  Have no record of the passcode, which it demands when touched. Googling says to click on Settings in thermostat display on wall.  Settings do not appear.  How do I reset passcode so I can control temperature in house?

[David_K · Accepted solution]

To resolve this, you'll need to reset it using a computer.

1. Connect the Nest Thermostat display via USB to a computer.
   
   
2. Verify that the Nest Thermostat mounts (appears as an attached drive icon).

• If the Nest drive will not mount: Restart the thermostat and the computer.
• If the Nest drive still won't mount: Connect another device to the cable to see if it appears as an installed device.
• If it doesn't appear, use a different cable/port/computer.

If the Nest drive is successfully showing up on your computer, can you see a technicalinfo.PLIST file? If you get this far let me know and I'll ask a community specialist to assist with next steps, as these can't be shared publicly in the community.